Detachable tablet arm and bookrack

ABSTRACT

This chair includes a detachable tablet arm and bookrack. The tablet arm includes a pair of supporting legs which pass beneath the air seat. Each leg includes a projecting tab which hooks into a receiving well created by a deformation in a seat supporting flange at the side of the chair. The ends of the legs are bolted to similarly formed receiving wells at opposite sides of the chair. The bookrack includes a platform which hooks over a crossbar joining the front legs of the chair. A supporting back projecting upwardly from the rear of the platform includes a pair of oppositely directed tabs for insertion into the rear receiving wells on the seat supporting flanges.

United States Patent 11 1 Baker et a1.

[ 1 June 4, 1974 DETACHABLE TABLET ARM AND BOOKRACK [75] lnventors: Richard H. Baker; Donald E.

McNally; Michael J. Armstrong, all of Grand Rapids, Mich.

[73] Assignee: Steelcase lnc., Grand Rapids, Mich,

[221 Filed: June 7, 1972 [21] Appl. N0.: 260,448

[52] US. Cl 297/160, 297/192, 297/416,

Miller et al. 297/160 X FOREIGN PATENTSOR APPLICATIONS 550,583 12/1957 Canada 297/160 Primary Examiner-James T. McCall Attorney, Agent, or Firm-Price, Heneveld, Huizenga & Cooper 5 7 1 ABSTRACT This chair includes a detachable tablet arm and bookrack. The tablet arm includes a pair of supporting legs which pass beneath the air seat. Each leg includes a projecting tab which hooks into a receiving well created bya deformation in a seat supporting flange at the side of the chair. The ends of the legs are bolted to similarly formed receiving wells at opposite sides of the chair. The bookrack includes a platform which hooks over a crossbar joining the front legs of the chair. A supporting back projecting upwardly from the rear of the platform includes a pair of oppositely directed tabs for insertion into the rear receiving wells on the seat supporting flanges.

24 Claims, 11 Drawing Figures PATENTEDJHH 41974 3 14 7 SHEET 3 BF 5 FIG.5

PATENTED M914 Bis-14.474

SHEET U 0F 5 1 DETACHABLE TABLET ARM AND BOOKRACK BACKGROUND OF THE INVENTION The present invention relates to attachments for chairs. More specifically, it relates to optional tablet arm and bookrack attachments which serve to increase the versatility of a chair. The invention is-particularly well-adapted for use with stacking chairs. An example of such chairs is disclosed in patent application Ser. No. 111,429, owned by the assignee of this invention, invented by Randall P. Buhk, et al, and filed Feb. I, 1971.

Conventionally, tablet arms comprise a wooden arm member supported by a frame connected to the chair. This frame generally includes a pair of leg members passing beneath the seat and being bolted to the frame of the chair, generally at each side of the chair. This requires four sets of bolts and four bolting operations. To perform the operation quickly, two people are required. One must hold the frame in place while the other bolts it down. Some prior art chair and tablet arm combinations even require the removal of the seat prior to attaching the tablet arm, in order that the same bolts may be used to hold both the seat and the tablet am.

As an alternative to bolts, the arms may pass through tubular members positioned beneath the seat. One problem with this is that it is diffuclt to slide the arms through the tubes, if any type of snug fit is to be achieved. In the alternative, the tubes may be twosection members which can be loosened for sliding the arms therethrough and which can then be retightened. The only problem with such an arrangement is that this also requires a number of different bolting and unbolting operations.

Conventional bookrack attachments are similarly generally bolted to the chairs. Some prior art bookracks hang over cross-pieces between the legs of the chair, and include rod portions wrapped around the crosspieces. In the latter case, however, the bookracks are generally not readily attachable or detachable.

SUMMARY OF THE INVENTION In the present invention, a chair is provided having readily attachable tablet arm, or bookrack, or both. In the case of each attachment, mounting is facilitated by the attachment member including a tab projecting from a supporting portion thereof into a receiving means disposed beneath the chair seat.

In the case of tablet arm, for example, the arm has at least one supporting leg passing beneath the seat of the chair. The tab is secured to and projects from this supporting leg. Preferably, the tab is generally positioned at one side of the seat and the leg includes a securing means positioned beneath the seat and generally at the opposite side thereof. The chair includes "engaging means for matingly engaging the securing means. By positioning the tab in the receivingmeans, one can positively locate and hold the tablet arm while effecting engagement of the securing and engaging means. In fact, the invention further contemplates that the tab and receiving means will be located on that side of the chair which is adjacent the tablet arm such that the tablet arm is held in place and balanced by the tab engaging the receiving means while one completes the assembly of the securing means to the engaging means. Such a structure makes the job of attaching the tablet arm to the chair a simple, one man operation. Further, the

load of a person resting on the tablet arm is transmitted to the frame by a position interfit or interlock between the tablet arm and frame. This gives positive security against the tablet arm collapsing; If bolts or screws were used at this point, they might loosen and fall out under load.

In the case of the bookrack, the bookrack includes a platform which is secured generally to the front of the chair by means on the platform and chair which cooperate to effect such securance. Theplatform includes a support depending upwardly therefrom, generally near the rear thereof. This support includes a tab projecting therefrom for insertion into the receiving means positioned generally beneath the seat. In this manner, positive locating and holding of the bookrack can be effected without any bolting at all. Preferably, the support includes spaced legs joined at their upper ends by a crosspiece. The crosspiece is broken between the legs and includes joining means for holding the separate crosspiece portions together. Each of the crosspiece portions includes a tab, with the two tabs projecting in opposite directions, away from each other. The chair then includes a receiving means positioned generally at opposite sidesof the chair for receiving each of the tabs. The bookrack itself is preferably sufficiently resiliently flexible that the crosspiece portions can be separated and compressed inwardly towards one another to facilitate insertion of the tabs into the receiving means.

For attaching the bookrack and tablet arm simultaneously, the same receiving means at the back 'of the chair is specially adapted for holding the tabs of both the tablet arm and bookrack. Preferably, receiving means are positioned on either side of the chair to facilitate the mounting of the bookrack and to make it possible to mount either a left or right-handed tablet arm.

Finally, the objects of the present invention are further facilitated by the specific construction of the tab member. Each of the tab members is joined to the tablet arm leg or to the bookrack support by an upwardly depending side wall joined to a base projecting generally laterally therefrom. The tab itself projects outwardly from the base. A portion of one of the side walls projects beyond the end of the base in the same direction as the tab, but the side wall portion is spaced from the tab and projects at a level which is below that of the tab. The receiving means on the chair which cooperates with this tab member comprises a well defining a recess for receiving the tab. The well includes a notch therein into which the, side wall of the tab can be inserted with its projecting portion passing beneath the well and with its tab overlying the top of the well. This unique structure results in a more positive interlock between the tab and the receiving means.

These and other objects and advantages of the present invention .will further be understood and appreciated by reference to the written specification and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 is a front elevational view of the tablet arm supporting frame;

FIG. 5 is a bottom plan view of one side of the chair seat showing the tabs on the tablet arm supporting frame-and on the bookrack as they are about to pass into mating engagement with the receiving means on the bottom of the chair seat;

FIG. 6 is the same viewas FIG. 5 with the aforesaid tabs being positioned in such mating engagement;

FIG. 7 is a top plan view of a portion of the chair frame, with the seat removed, showing the tab of a supporting leg for the tablet arm in mating engagement with a receiving means on the chair frame;

FIG. 8 is a cross-sectional view taken along plane VIIIVIII of FIG. 3, with a supporting leg of the tablet arm being secured to the chair frame; I

FIG. 9 is a front elevational view of the bookrack;

FIG. 10 is a sideelevational view of the bookrack;

and

FIG. 11 is a top plan view of one side portion of the bookrack.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment, the chair 10 (FIG, 1) includes a front receiving well and arear receiving well30 at each side of the seat thereof for mating engagement with leg tab members 50 on the front and rear supporting legs 42 and 43, respectively, of tablet arm 40, (FIGS. 2 through 7). Rear wells 30 are also adapted for cooperation with the crosspiece tab members 70 on the rear of bookrack 60 (FIG. 2, 5, 6 & 9). With tablet arm 40 and bookrack 60 assembled to chair 10, chair 10 takes on the appearance shown in FIG. 2.

Chair 10 is of the wire rod, stacking variety. It is bascially similar in construction to the stacking chair described and claimed in patent application, Ser. No.

lll,429 filed Feb.v l, 1971, entitled CHAIR, and

owned by the assignee of the present invention. It includes a wire rod frame 13 for supporting a seat 14 and back 15 (FlG. l). (Ionnected to the sides of wire rod frames 13 for facilitating the support of seat 14 are a pair of side flanges 11 (FIG. 3). Side flanges 11 are preferably stamped from metal and welded to wire rod frame 13. Each includes several apertures for receiving bolts 12 which secure seat 14 thereto.

Front receiving well 20 is formed by a deformation downwardly in each side flange 11 (FIGS. 3 and 8). This leaves a space between the bottom of seat 14 and the top of each receiving well 20.

Each front receiving well 20 includes a pair of spaced notches 21 which define a tongue 22 (FIG. 3). Notches- 21 and tongue 22 cooperate with leg tab member. 50 in the manner which is shown in FIGS. 58: 6 and which will be more fully described hereinafter. Receiving well 20 also includes an aperture 23 therethrough which acts as an engaging means for the end of front tablet arm supporting leg 42 in the manner which is shown in FIG. 8 and which will be more fully described hereinafter.

Each of the rear receiving wells 30 is similarly formed by a downward deformation at the rear of each side flange 11 F IG.'3). Each rear receiving well 30 includes a front notche 31, a middle notch 32 and a rear notch 33. Front notch 31 and middle notch 32 are space to define a front tongue 34 which corresponds generally to tongue 22. Middle notch 32 and rear notch 33 define a rear tongue 36. Front and middle notches 31 and 32 and front tongue 34 cooperate with the leg tab on the rear leg 43 of tablet arm 40 in the same manner as tongue 22 and notches 21' cooperate with leg tab member 50 on front supporting leg 42 (FIGS. 5 & 6). Rear tongue 35 and rear notch 33 cooperate with crosspiece tabs 70 on bookrack 60 in the manner which is shown in FIGS. 5 & 6 and which will be more fully described hereinafter. Rear well 30 also includes'an aperture 36 for engaging the end of rear leg 43, just as the end of leg .42 cooperates with aperture 23.

Tablet arm 40 comprises an arm platform 41 supported generally by the upper support portion 48 of a front leg 42 and rear leg 43 (FIGS. 2 and 4). The specific connection between the upper support portion 48 and arm platform 41 is generally conventional in nature and facilitates the pivotal movement of arm platform 41 upwardly to simplify the task of sitting down-in or arising from chair 10. Front legs'42 and rear leg 43 extend downwardly from arm platform 41 and then project inwardly to pass beneath seat 14 of chair 10.

Both front leg 42 and rear leg 43 of tablet arm 40 include a leg tab member 50 secured thereto (FIG. 4). Each leg tab member 50 is secured to legs 42 and 43 at a point beneath chair seat 14 near the point where legs 42 and 43 prbject inwardly and pass beneath seat 14. When tablet arm assembly 40 is secured to chair l0, leg tab 50 is positioned generally adjacent that side of .seat 14 which is adjacentarm platform 41.

Each leg tab member 50 includes a side wall 51 and a spaced side wall 53 joined to-a base 52 (FIG. 5). Leg tab member 50 is'preferably formed of metal and side walls 51 and 53 are preferably secured to leg 42 or leg 43 respectively bywelding. Tab 54 projects outwardly from base 52. Y Y

Projectingfrom base 52 is tab 54. Side walls 51 and 53 project upwardly fromjleg 42 such that tab 54 is spaced above either leg 42 orleg 43 (FIG. 4). Tab 54 projects from base 52 generally towards tablet arm platform 41, rather than towards the opposite end of leg 42 or 43. The fact that tab 54 points in this direction helps insure that it will not become accidentally disengaged from receiving walls '20 or 30 when seat 14 is sat upon. If tab 54 werepointed inwardly with its receiving well 20 or 30 opening outwardly, the compressive force tending to compress the sides of the chair 10 inwardly when seat 14 is sat upon, even though slight, might tend to cause tab 54 to disengage from its respective receiving well 20 or 30. By orienting tabs 54 and receiving wells 20 and 30 according to the present invention, any compressive force tending to move the sides of the chair 10 inwardly will merely tend to further force tab 54 into either receiving well 20 or 30.

Side wall 51, 0f tab member 50 includes a portion 55 projecting beyond the'end of base 52 generally in the direction of tab 54 (FIG. 5). Projecting portion 55 projects at a level spaced below the level of tab 54 (FIG. 4). Thus when'tab 54 is inserted into front receiving well 20, projecting portion 55 is positioned below the surface of receivingwell 20 while tab 54 is positioned above the surface of receiving well 20 (FIG. 6). Side wall 51 proper is then received in notch 21 and side wall 53 is received in the opposite notch 21. Thus tab 54 specifically overlies tongue 22 of receiving well 20. In this manner, tab member 50 is positively held in place and is restrained from lateral movement, vertical up and down movement and longitudinal movement in a direction towards the outside of chair l0.

Tab 50 on rear leg 43 cooperates with rear receiving well 30 in the same manner. Thus, side wall 51 is received within middle notch 32, side wall 53 is received within front notch 31, projecting portion 55 is positioned beneath the surface of receiving well 30 and tab 54 is positioned above front tongue 34.

The end of front leg 42 and of rear leg 43 includes an aperture 44 therethrough for receiving a bolt 45 (FIGS. 4 and 8). Bolt 45 in front leg 42 extends upwardly and passes through aperture 23 in receiving well and is threaded into a special nut 46 which is disposed within front receiving well 20. The space between seat 14 and front receiving well 20 makes it possible to place nut 46 in this position. Nut 46 is specially adapted for this purpose, having a hook portion 47 which hooks over the edge of receiving well 20. By pushing nut 46 inwardly until hook 47 is stopped by the edge of receiving well 20, one pretty well located the threaded aperture of nut 46 over aperture 23. Further, hook 47 prevents nut 46 from turning when bolt 45 is threaded thereinto.

Rear leg 43 includes an identical aperture 44 at its end for cooperating in an identical manner with a bolt 45 and nut 46 having a hook portion 47. For rear leg 43, bolt 45 passes through aperture 36 in rear receiving well 30.

Bookrack .60 is formed of a plurality of wire rods welded together (FIG. 2). ltincludes a book supporting platform 61 joined to a back 62. Back 62 serves not only to prevent books from being slid off the back of platform 61, but also as a support for platform 61.

Thus, back 62 includes a pair of spaced legs 63 projecting upwardly from either side of platform 61, generally at the rear thereof (FIGS. 9 throughll). Legs 63 are joined by a crosspiece 65 which is broken in the middle into two separate crosspiece portions. A cylindrical, tubular joining tube 66 is welded to one of the crosspiece portions 65 and is open at its other end such that the other crosspiece portion 65 can be inserted thereinto.

A crosspiece tab member 70, preferably formed of metal, is welded to each crosspiece portion 65 near its juncture with its respective leg 63. Each tab member 70 includes a sidewall 71 secured to and projecting upwardly from crosspiece portion 65 and being joined to and integral with a laterally projecting base 72 (FIGS. 9 and 5). A tab 73 projects from base 72 with each of the two tab members 70 being oriented such that the tabs 73 project in opposite directions away from each other and away from the center of crosspiece 65. Side wall 71 includes a portion 74 projecting therefrom in the. same direction as tab 73 projects, but at a level spaced below tab 73. Thus when tab 73is inserted into rear receiving well 30, it overlies rear tongue 35 (FIGS. 5 and 6). Wall 71 is received within rear notch 33 and projecting wall portion 74 is positioned beneath rear receiving well 30. In this manner, tab member 70 is snugly received in and mated to rear receiving well 30.

Bookrack 60 is made such that is has sufficient resilient flexibility that the separate crosspiece portion 65 can be separated one of said crosspiece members 65 being removed from joining tube 66, and then compressed inwardly toward one another in overlapping fashion to facilitate the insertion of tabs 73 into rear receiving wells 30. The end of one of the crosspiece portions 65 is then reinserted into joining tube 66 such that V of the invention.

the tabs 73 are positively held within rear receiving wells 30 by a rigid crosspiece extending between tab members (FIG. 9). In the preferred embodiment, the flexibility of bookrack 60 is provided primarily by the wire rod supporting legs 63.

The front of platform 61 is secured to the front of chair l0'by means of hooks 67 formed at the ends of the side rods 68 of platform 61 (FIGS. 2, 9 and 10). These hook over a cross-brace 16 which extends between the two front legs 17 of chair 10. Thus, the front of platform 61 is supported at the front of chair 10 while the rear thereof is supported at the rear of chair l0.

OPERATION In operation, either tablet arm 40 or bookrack 60, or both, can be readily mounted to chair 10. In order to mount tablet arm 40 to chair 10, legs 42 and 43 are passed beneath seat 14 and tabs 54 on leg tab members 50 are hooked into front receiving well 20 and rear receiving well 30 respectively. Tablet arm 40 is thereby held in place and can easily be balanced while bolt 45 is passed through aperture 44 at the end of each leg 42 and 43 and through either aperture 23 or 36 and is secured to nut 46. The force or load placed on tablet arm 40 by a person leaning thereon is transmitted to frame 10 by the positive interlock between tabs 54 and receiving wells 20. This positive interlock insures that tablet arm 40 will not inadvertantly collapse under load. Bolts 45 are used only on the side of frame 10 opposite platform 41 and therefore are not subjected to a force'tending to pull them loose. They need only be tightened sufficiently to prevent rattling.

Bookrack 60 is secured to chair It) by hooking hooks 67 over crossbrace 16. Then, being sure that crosspiece portions 65 are disengaged, side legs 63 of back 62 are compressed inwardly and crosspiece tab member 70 are placed in alignment with rear receiving wells 30. Legs 63 are then allowed to spring back outwardly such that tabs 73 will automatically pass into and be received by rear receiving wells 30. Tabs 73 are positively held within rear receiving wells 30 by again joining crosspiece portions 65 at joining tube 66.

With the attachments thus assembled, one has converted a wire rod stacking chair 10 into a tablet arm chair suitable for many instructional uses. This greatly increases the versatility of the basic chair 10. The fact that the present invention enables tablet arm 40 and bookrack 60 to be so easily attached to chair 10 is a significant factor in increasing the versatility of the chair. Of course, it will be understood that the above is merely a preferred embodiment of the invention and that many changes and alterations can be made thereof without departing from the spirit and broader aspects The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a chair with detachable bookrack and tablet arm, said tablet arm including an arm platform and at least one supporting leg depending therefrom and passing beneath the seat of said chair, the improvement comprising: said leg having a leg tab secured thereto and projecting therefrom; said bookrack including a platform, a support projecting upwardly therefrom and a support tab projecting from said support; said chair including receiving means connected thereto and positioned beneath said seat, said receiving means defining a recess for matingly receiving both said leg tab and said support tab.

2. The chair of claim 1 comprising: said leg tab being positioned generally at a first side of said seat; said leg including securing means positioned beneath said seat generally at the second side thereof; said bookrack support including spaced first and second legs joined at the upper ends by a crosspiece; said crosspiece being broken intermediate said legs and including means for joining the two portions thereof; each crosspiece portion including one of said support tabs, said support tabs projecting in opposite directions away from the center of said crosspiece; said chair including one of said receiving means for each of said support tabs, each of said receiving means being positioned generally at opposite sides of said chair with said recesses opening towards one another; each of said receiving means being adapted to receive both a support tab and said leg tab and each of said receiving means including engaging means for matingly engaging said securing means on said leg whereby said'tablet arm can be either a lefthanded or a right-handed tablet arm; said bookrack being sufficiently resiliently flexible that said crosspiece portions can be separated and compressed inwardly towards one another to facilitate insertion of said support tabs into said receiving means.

3. The chair of claim 2 in which: said first and second legs of said bookrack are resiliently flexible.

4. The chairof claim 2 comprising: said first side of said seat being that side of said seat adjacent said arm platform.

5. The chair of claim 4 in which said receiving means comprises: a well depending downwardly from said seat, leaving a space between the bottom of said seat and said well.

6. The chair of claim 5 in which said tablet arm includes a second leg depending downwardly therefrom and passing beneath the seat of said chair; said second leg being positioned forwardly of the first leg; said second leg including a tab being'secured thereto and projecting therefrom and said second leg including a securing means at its end; said chair includinga pair of front downwardly depending wells, each generally at the front and one at each side of said chair for matingly receivingsaid tab and each including an engaging means for engaging said securing means.

7. The chair of claim 5 in which: each said support tab for said book rack comprises: a side wall, a base and a tab, said side wall being secured to and projecting upwardly from said crosspiece portion, said base projecting generally laterally from said side wall and said tab projecting from said base; each said leg tab comprising a side wall, a base and a tab, said side wall being-secured to said leg and projecting upwardly therefrom, said base projecting generally laterally from said side wall; each said side wall of each said leg tab and said support tab including a portion projecting therefrom in the same direction as its respective tab, but at a lower level, spaced therefrom; each said receiving'means including a notch for receiving said side wall of said leg tab member and having a notch for receiving said side wall of said support tab member; said side walls resting in said respective notches, said tabs being positioned within said receiving means on the upper surface thereof and said projecting side wall portions being positioned below said receiving means.

8. The chair of claim 7 in which said chair seat is mounted on a pair of flanges, each'of said flanges being secured to said chair generally at the side thereof; each of said wells being defined by a downward deformation in 'said flange.

9. The chair of claim 8 in which said platform and said chair include means cooperating to secure said platform to said chair, said cooperating means being disposed generally at the front of said chair and at the front of said platform.

10. The chair of claim 9 in which said means cooperating comprise: at least one hook on the front of said platform and a crossbrace extending between and joining the front legs of said chair.

1 1. The chair of claim 1 in which: said support tab for said bookrack comprises: a side wall, a base and a tab, said side wall being secured to and projecting upwardly from said support, said base projecting generally laterally from said side wall and said tab projecting from said base; said leg tab comprising a side wall, a base and .a tab, said side wallbeing secured to said leg and projecting upwardly therefrom, said base projecting generbut at a lower level, spaced therefrom; said receiving means including a notch for receivingsaid side wall of said leg tab member and having a notch for receiving said side wall of said support tab member; said side walls resting in said respective notches, said tabs being positioned within said receiving means on the upper surface thereof and said projecting sidewall portions being positioned below said receiving means.

12. In a chair with detachable tablet arm,said tablet arm having an arm platform and at least one supporting leg depending downwardly therefrom and passing beneath the seat of said chair, the improvement comprising: said leg having a leg tab secured thereto and pro-v jecting therefrom; said chair including receiving means defining a recess beneath said seat for matingly receiving said leg tab to thereby support and locate said leg beneath said seat; said leg tab being positioned generally at a first sideof said seat; said leg including securing means positioned beneath said seat and generally at the second side of said seat; said chair including engag ing means positioned beneath said seat for matingly engaging said securing means. 7

13. The chair of claim 12 comprising: said first side of said chair being that side of said chair which is adjacent said arm platform.

14. The chair of claim 13 comprising: said leg tab projecting from said leg generally towards the side of said chair at which said tablet arm is located.

15. The chair of claim 14 in which said receiving means comprises: a well depending downwardly from said seat generally at said first side thereof.

16. The chair of claim 15 in which said leg tab comprises a side wall, a base and a tab, said side wall being secured to and projecting upwardly from said leg and said base projecting generally laterally from said side wall; said tab projecting outwardly from said base; said side wall including a portion projecting beyond the end of said base in the same direction as said tab, but being spaced from said tab at a level below that of said tab; said well including a notch therein for matingly embracing said side wall with said tab lying within said well on the upper surface thereof and said projecting side wall portion lying beneath said well on the underside thereof.

17. The chair of claim 16 in which said leg tab includes a second wall secured to said leg and projecting upwardly therefrom and then being joined to said base, said leg tab being generally U-shaped in configuration; said well including a second notch therein defining a tongue between said notches; said second side wall being matingly engaged by said second notch and said tab overlying said tongue.

18. The chair of claim 16 in which said engaging means comprises: a second well depending downwardly from said seat, generally at said second side thereof; said well having an aperture therein; said securing means comprising a bolt passing through the end of said leg and through said aperture; the space between said receiving well and seat being sufficiently large that a nut can be inserted therein; a nut being inserted in said well with said bolt being threaded in said nut.

19. The chair of claim 18 in which: said nut includes a hook on one side thereof for hooking over the edge of said receiving well to facilitate locating said out with respect to said aperture and to prevent said nut from rotating when said bolt is threaded thereinto.

20. The chair of claim 18 in which: said second well and the first well are identical in structure whereby said tablet arm can either be a left-handed or a right-handed tablet. arm.

21. The chair of claim 18 in which said chair seat is mounted on a pair of flanges, each of said flanges being secured to said chair generally at the side thereof; each of said wells being defined by a downward deformation in said flange.

22. The chair of claim in which said tablet arm includes a second leg depending downwardly therefrom and passing beneath the seat of said chair; said second leg being positioned forwardly of the first leg; said second leg including a tab being secured thereto and projecting therefrom sand said second leg including a securing means at its end; said chair including a front downwardly depending well generally at the front and at each side of said chair for matingly receiving said tab and including an engaging means for engaging said securing means.

23. The chair of claim 15 in which said chair seat is mounted on a pair of flanges, each of said flanges being secured to said chair generally at the side thereof; each of said wells being defined by a downward deformation in said flange.

24. In a chair having a detachable bookrack and tablet arm, said tablet arm including a pair of legs depending downwardly therefrom and passing beneath said seat, said chair including a flange at either side thereof for supporting the chair seat, the improvement comprising: each of said legs including a tab projecting upwardly therefrom and towards said tablet arm; said tabs being positioned beneath said seat generally at the side adjacent said tablet arm; each of said flanges including a pair of deformations therein in a downward direction away from the bottom of said seat, said deformations defining receiving wells for receiving said tabs at either side of said seat whereby either a left-hand or righthand tablet arm can be mounted to said chair; each of said legs including securing means at the end thereof for securing to the receiving wells at the side of said chair away from said tablet arm; said bookrack including a platform and a pair of legs projecting upwardly generally from the rear thereof, said legs being joined by a cross-piece which is broken intermediate said legs; said crosspiece including means detachably joining the two portions thereof; cooperating means disposed generally at the front of said chair and said platform cooperating to secure said platform to said chair; each portion of said crosspiece including a tab projecting upwardly from said crosspiece and outwardly away from each other; one of said receiving wells on each of said flanges being generally at the rear of said seat and being.

sufficiently large to receive one of said crosspiece tabs and one of said leg tabs. 

1. In a chair with detachable bookrack and tablet arm, said tablet arm including an arm platform and at least one supporting leg depending therefrom and passing beneath the seat of said chair, the improvement comprising: said leg having a leg tab secured thereto and projecting therefrom; said bookrack including a platform, a support projecting upwardly therefrom and a support tab projecting from said support; said chair including receiving means connected thereto and positioned beneath said seat, said receiving means defining a recess for matingly receiving both said leg tab and said support tab.
 2. The chair of claim 1 comprising: said leg tab being positioned generally at a first side of said seat; said leg including securing means positioned beneath said seat generally at the second side thereof; said bookrack support including spaced first and second legs joined at the upper ends by a crosspiece; said crosspiece being broken intermediate said legs and including means for joining the two portions thereof; each crosspiece portion including one of said support tabs, said support tabs projecting in opposite directions away from the center of said crosspiece; said chair including one of said receiving means for each of said support tabs, each of said receiving means being positioned generally at opposite sides of said chair with said recesses opening towards one another; each of said receiving means being adapted to receive both a support tab and said leg tab and each of said receiving means including engaging means for matingly engaging said securing means on said leg whereby said tablet arm can be either a left-handed or a right-handed tablet arm; said bookrack being sufficiently resiliently flexible that said crosspiece portions can be separated and compressed inwardly towards one another to facilitate insertion of said support tabs into said receiving means.
 3. The chair of claim 2 in which: said first and second legs of said bookrack are resiliently flexible.
 4. The chair of claim 2 comprising: said first side of said seat being that side of said seat adjacent said arm platform.
 5. The chair of claim 4 in which said receiving means comprises: a well depending downwardly from said seat, leaving a space between the bottom of said seat and said well.
 6. The chair of claim 5 in which said tablet arm includes a second leg depending downwardly therefrom and passing beneath the seat of said chair; said second leg being positioned forwardly of the first leg; said second leg including a tab being secured thereto and projecting therefrom and said second leg including a securing mEans at its end; said chair including a pair of front downwardly depending wells, each generally at the front and one at each side of said chair for matingly receiving said tab and each including an engaging means for engaging said securing means.
 7. The chair of claim 5 in which: each said support tab for said bookrack comprises: a side wall, a base and a tab, said side wall being secured to and projecting upwardly from said crosspiece portion, said base projecting generally laterally from said side wall and said tab projecting from said base; each said leg tab comprising a side wall, a base and a tab, said side wall being secured to said leg and projecting upwardly therefrom, said base projecting generally laterally from said side wall; each said side wall of each said leg tab and said support tab including a portion projecting therefrom in the same direction as its respective tab, but at a lower level, spaced therefrom; each said receiving means including a notch for receiving said side wall of said leg tab member and having a notch for receiving said side wall of said support tab member; said side walls resting in said respective notches, said tabs being positioned within said receiving means on the upper surface thereof and said projecting side wall portions being positioned below said receiving means.
 8. The chair of claim 7 in which said chair seat is mounted on a pair of flanges, each of said flanges being secured to said chair generally at the side thereof; each of said wells being defined by a downward deformation in said flange.
 9. The chair of claim 8 in which said platform and said chair include means cooperating to secure said platform to said chair, said cooperating means being disposed generally at the front of said chair and at the front of said platform.
 10. The chair of claim 9 in which said means cooperating comprise: at least one hook on the front of said platform and a crossbrace extending between and joining the front legs of said chair.
 11. The chair of claim 1 in which: said support tab for said bookrack comprises: a side wall, a base and a tab, said side wall being secured to and projecting upwardly from said support, said base projecting generally laterally from said side wall and said tab projecting from said base; said leg tab comprising a side wall, a base and a tab, said side wall being secured to said leg and projecting upwardly therefrom, said base projecting generally laterally from said side wall and said tab projecting from said base; each said side wall of each said leg tab and said support tab including a portion projecting therefrom in the same direction as its respective tab, but at a lower level, spaced therefrom; said receiving means including a notch for receiving said side wall of said leg tab member and having a notch for receiving said side wall of said support tab member; said side walls resting in said respective notches, said tabs being positioned within said receiving means on the upper surface thereof and said projecting side wall portions being positioned below said receiving means.
 12. In a chair with detachable tablet arm, said tablet arm having an arm platform and at least one supporting leg depending downwardly therefrom and passing beneath the seat of said chair, the improvement comprising: said leg having a leg tab secured thereto and projecting therefrom; said chair including receiving means defining a recess beneath said seat for matingly receiving said leg tab to thereby support and locate said leg beneath said seat; said leg tab being positioned generally at a first side of said seat; said leg including securing means positioned beneath said seat and generally at the second side of said seat; said chair including engaging means positioned beneath said seat for matingly engaging said securing means.
 13. The chair of claim 12 comprising: said first side of said chair being that side of said chair which is adjacent said arm platform.
 14. The chair of claim 13 comprising: said leg tab projectinG from said leg generally towards the side of said chair at which said tablet arm is located.
 15. The chair of claim 14 in which said receiving means comprises: a well depending downwardly from said seat generally at said first side thereof.
 16. The chair of claim 15 in which said leg tab comprises a side wall, a base and a tab, said side wall being secured to and projecting upwardly from said leg and said base projecting generally laterally from said side wall; said tab projecting outwardly from said base; said side wall including a portion projecting beyond the end of said base in the same direction as said tab, but being spaced from said tab at a level below that of said tab; said well including a notch therein for matingly embracing said side wall with said tab lying within said well on the upper surface thereof and said projecting side wall portion lying beneath said well on the underside thereof.
 17. The chair of claim 16 in which said leg tab includes a second wall secured to said leg and projecting upwardly therefrom and then being joined to said base, said leg tab being generally U-shaped in configuration; said well including a second notch therein defining a tongue between said notches; said second side wall being matingly engaged by said second notch and said tab overlying said tongue.
 18. The chair of claim 16 in which said engaging means comprises: a second well depending downwardly from said seat, generally at said second side thereof; said well having an aperture therein; said securing means comprising a bolt passing through the end of said leg and through said aperture; the space between said receiving well and seat being sufficiently large that a nut can be inserted therein; a nut being inserted in said well with said bolt being threaded in said nut.
 19. The chair of claim 18 in which: said nut includes a hook on one side thereof for hooking over the edge of said receiving well to facilitate locating said nut with respect to said aperture and to prevent said nut from rotating when said bolt is threaded thereinto.
 20. The chair of claim 18 in which: said second well and the first well are identical in structure whereby said tablet arm can either be a left-handed or a right-handed tablet arm.
 21. The chair of claim 18 in which said chair seat is mounted on a pair of flanges, each of said flanges being secured to said chair generally at the side thereof; each of said wells being defined by a downward deformation in said flange.
 22. The chair of claim 15 in which said tablet arm includes a second leg depending downwardly therefrom and passing beneath the seat of said chair; said second leg being positioned forwardly of the first leg; said second leg including a tab being secured thereto and projecting therefrom sand said second leg including a securing means at its end; said chair including a front downwardly depending well generally at the front and at each side of said chair for matingly receiving said tab and including an engaging means for engaging said securing means.
 23. The chair of claim 15 in which said chair seat is mounted on a pair of flanges, each of said flanges being secured to said chair generally at the side thereof; each of said wells being defined by a downward deformation in said flange.
 24. In a chair having a detachable bookrack and tablet arm, said tablet arm including a pair of legs depending downwardly therefrom and passing beneath said seat, said chair including a flange at either side thereof for supporting the chair seat, the improvement comprising: each of said legs including a tab projecting upwardly therefrom and towards said tablet arm; said tabs being positioned beneath said seat generally at the side adjacent said tablet arm; each of said flanges including a pair of deformations therein in a downward direction away from the bottom of said seat, said deformations defining receiving wells for receiving said tabs at either side of said seat whereby either a left-hand or right-hand tablet arm can be mOunted to said chair; each of said legs including securing means at the end thereof for securing to the receiving wells at the side of said chair away from said tablet arm; said bookrack including a platform and a pair of legs projecting upwardly generally from the rear thereof, said legs being joined by a cross-piece which is broken intermediate said legs; said crosspiece including means detachably joining the two portions thereof; cooperating means disposed generally at the front of said chair and said platform cooperating to secure said platform to said chair; each portion of said crosspiece including a tab projecting upwardly from said crosspiece and outwardly away from each other; one of said receiving wells on each of said flanges being generally at the rear of said seat and being sufficiently large to receive one of said crosspiece tabs and one of said leg tabs. 